Ecotype differentiation of Ribes rubrum in Norway

Summary Clones of Ribes spp. from 6 regions in Norway and from Denmark, together with a commercial variety, had shown differences in phenological and morphological characters. However, some crossing between wild and cultivated material was suspected to have occurred. A cluster analysis was performed in order to regroup the clones. The results for both vegetative and generative characters showed that most of the clones had a common origin. Some differentiation had occurred between wild and cultivated types and also between northern and southern types (north and south of 61° N resp.). These may be considered to be different ecotypes. The pattern is compared with that of other species.     

Species relationships in the subgenus Ceratotropis (genus Vigna) as revealed by RAPD analysis

Summary The genetic variation among 23 accessions of 5 species in the subgenus Ceratotropis, genus Vigna, were investigated by random amplified polymorphic DNA (RAPD) analysis. A total of 404 fragments amplified with 24 primers were scored and analyzed by cluster analysis. The accessions used were separated into two main groups with an average of 70% differences. Within the main groups, five subgroups were recognized, which are in complete agreement with taxonomic species. Wild forms were always grouped with their most closely related cultivated forms and they showed variation in each species. The largest intraspecific variation was found in V. radiata (mungbean), in which wild forms (V. radiata var. sublobata) were highly different from each other and from cultivated forms. V. angularis (adzuki bean) showed the least variation and thus, was probably differentiated in relatively recent times.     

Characterization of common bean wild populations for their in situ conservation in Northwestern Argentina

In situ conservation of wild species is a method of conservation that allows keeping populations in their natural environments, and set the strategies for maintaining the natural populations. The Active Bank of Northwestern Argentina (BANOA) is in charge of the in situ conservation of wild populations of common bean (Phaseolus vulgaris L.) in Northwestern Argentina (NOA), and has an ex situ collection of 401 landraces and 221 wild accessions from the NOA. We evaluated the phenotypic diversity of 68 common bean wild populations from the NOA both in protected and unprotected areas, finding a moderate variation among them. Ten phenotypic reproductive characteristics related to pod and seed displayed significant differences in the analysis of variance; these traits together with the seed weight were the basis for the multivariate analysis. The cluster analysis ordered the populations in 12 groups but trends in geographical distribution or phenotypical variation were not recognized. For the conservation in situ of the wild bean populations, their diversity should be considered. Two types of populations can be highlighted: (i) candidates for in situ conservation in order to preserve the novel variation generated by convergence with cultivated sympatric germplasm (populations 433, 437, 471, 509, 513 and 517) and (ii) those whose phenotype represents clearly the wild status and should be preserved in situ as such in their current status (populations 480, 495, 496, 525 and 533).     

Assessment of genetic variation among asparagus (Asparagus officinalis L.) populations and cultivars: agromorphological and isozymic data

Summary The morphological variation and the isozymic polymorphism in 19 asparagus accessions currently used in cultivation and breeding are described. Moreover 2 wild populations from Turkey were added in the isozymic study. Characters of ramification height permit to separate accessions usually cultivated for white asparagus and accessions usually cultivated for green asparagus. Starch and polyacrylamide gel electrophoresis was realized to assay 7 enzyme systems. 29 polymorphic bands were taken into account in the study. Four accessions show specific bands for glutamate oxaloacetate transaminase, shikimate dehydrogenase and alcohol dehydrogenase. In particular, the two populations from Turkey and one population traditionally cultivated in local area of Spain are well differentiated from the remaining accessions. Accessions from the United States representing different selections are relatively well separated from each other.     

Variation in Cicer arietinum L.

Summary A collection of populations and cultivars of Cicer arietinum L. were studied to obtain phenotypic, genotypic and environmental correlation coefficients, and broad sense heritabilities. Principal Component Analyses were performed on phenotypic, genotypic and environmental matrices. Data and phase obtained on a pure morphological basis, as well as on quantitative genetic studies and geographical distribution support the existence of two complexes within the cultivated chickpea, macrosperma and microsperma. These taxa differ in a cluster of complex characters associated with seed. pod and leaf morphology, and they differ in distribution. There is no taxonomic basis to treat these as subspecies. We propose to include C. reticulatum Lad., the wild chickpea, as a subspecies of C. arietinum, with the cultivated kinds recognized as subspecies arietinum. Race macrosperma was derived from race microsperma through selection during relatively recent times of the evolutionary history of the chickpea.     

Genetic diversity in red clover (Trifolium pratense L.) revealed by morphological and microsatellite (SSR) markers

The NPGS-USDA core collection with 85 accessions of red clover, an important forage species, is little described. The goal of the present study was to evaluate the diversity of a set of accessions from the core collection at the morphological and molecular level in order to extract some valuable accessions for Brazilian red clover breeding programs. Twenty-one morphological traits, collected in field and greenhouse in South Brazil, and seven SSR markers were used to describe 57 accessions from the U.S. core collection and one population cultivated in Southern Brazil. Variation between accessions was large for most of the 21 morphological traits. A cluster analysis based on the morphological traits revealed five distinct clusters that separated the populations according to flowering earliness, as already described, but also according to persistency, growth habit and dry matter productivity. Over seven SSR loci, the number of alleles averaged 11.1 alleles per locus. Genetic diversity measured with SSR markers was high, with a mean expected heterozygosity of 0.86. An analysis of molecular variance revealed that the largest proportion of variation (83.6%) resided at the within population level. Although the molecular markers also separated accessions into five clusters, there was no coincidence between the composition of groups found with morphological and molecular data. Use of genetic diversity in breeding programs requires to use the most promising populations, to combine positive traits such as persistency and forage yield, and probably to use within population variation to detect valuable genotypes that could be used as parents of synthetic varieties.     

Genetic divergence in parental genotypes and its relation with heterosis, F1 performance and general combining ability (GCA) in opium poppy (Papaver somniferum L.)

Summary Genetic divergence in 110 population (20 parents and 90 F₁ hybrids) of opium poppy was studied by multivariate analysis. All the entries were grouped in 14 clusters. Out of 20 parents, ten were accumulated in one cluster and rest 10 distributed over seven clusters. Estimates of cluster distance showed that maximum intra-cluster distance was in -cluster IX (25.62) followed by cluster I (22.41), V (22.23) and IV (21.06). The inter cluster distances varied from 16.62 (between cluster XII and XIV) to 195.10 (between cluster IV and IX). The cluster analysis indicated substantial diversity among the parental genotypes, which had the potential to release considerable variation in their crosses. The first four principal components (PCs) with eigen values >1 accounted for 68% of variation among the population. The first and second components could account for 29 and 20% of the total morphological and alkaloidal variations, respectively. The PC1 was closely related to yield and yield related traits. The characters contributing greatest positive weight on PC1 were opium yield, plant height, stem diameter, capsule weight/plant and seed yield/plant. The possibilities of relationship between genetic divergence, F₁ performance, heterosis and GCA of parents have been explored.     

濒危植物长叶榧种子形态变异研究

长叶榧(Torreya jackii)为中国特有的濒危保护植物。以长度、宽度作为种子大小的指标,长宽比作为种子形状的指标,对长叶榧自然种群间以及种群内个体间的种子形态变异进行研究,并分析了种子形态特征与环境因子的相关性。结果表明:长叶榧种子形态特征在种群内和种群间均存在一定程度的变异,长度、宽度在种群间差异极显著,长宽比在种群间显著差异;长叶榧种子形态变异最大的是长度,其次为宽度,长宽比的变异相对较小;长叶榧种子形态特征与环境因子的相关性不显著。     

Genetic diversity and relationships among Lablab purpureus genotypes evaluated using RAPD as markers

Summary Genetic variation in 40 accessions of Lablab purpureus was evaluated using random amplified polymorphic DNA as markers. A high level of genetic variation in this species was detected but this was mainly restricted to the difference between cultivated and wild forms. Of the cultivated genotypes, genetic variation among Asian collections was significantly higher than that among African collections. The three most divergent cultivated genotypes were all from Asia. Four of the five wild accessions, two from Zimbabwe and the other two from Zambia, were closely related. The other one, CPI 31113 collected from Uganda, was highly divergent. The two commercial forage varieties used in Australia, Rongai from Kenya and Highworth from India, were not very different.     

抗青枯病花生种质的遗传多样性

以栽培种花生2个亚种4个植物学类型的31份对青枯病具有不同抗性的种质为材料,通过SSR和AFLP技术分析了其DNA多样性,并与通过形态和种子品质性状揭示的表型多样性进行了比较。结果表明,不同类型的抗青枯病花生品种之间存在丰富的DNA多样性,SSR揭示的品种间遗传距离大于AFLP揭示的品种间遗传距离,基于二者的聚类分析结果趋势一致,结合花生的植物学类型、地理来源和系谱分析,以SSR的聚类结果与表型性状的聚类结果更为吻合。感病优质高产品种“中花5号”与密枝亚种的普通型和龙生型的抗病材料的差异很大,与育种中被广泛利用的抗源“协抗青”和“台山三粒肉”的差异相对较小,与“远杂9102”的差异更小。     

Conservation of diversity in bulk populations of barley (hordeum vulgare L.)

Summary A series of experiments was conducted to investigate the effectiveness of mass propagated heterogeneous populations (bulk populations) in preserving genetic and phenotypic diversity. Five genetically broad-based bulk populations of cultivated barley (Hordeum vulgare L.) were employed. All of them were produced originally through mass hybridization that was facilitated by male sterility. Four of these populations had a common origin, but were subsequently propagated in different North American locations. Comparisons between early and advanced generations of these bulk populations revealed loss of variability in all populations for morphological and agronomic characters and very little to none for eight isozyme characters. Populations propagated in different locations differed in levels of residual diversity. The bulk populations were less variable than a random sample of parental accessions. The rapid loss of diversity in bulk populations was considered detrimental to genetic conservation.     

棉属野生种克劳茨基棉(Gossypium klotzschianum)基因组向陆地棉的渐渗

 棉花远缘种质是改良栽培种的丰富资源,野生种遗传变异的有效利用依赖于鉴定并渐渗理想的野生种DNA进入栽培种的能力。为了检测二倍体野生种克劳茨基棉染色质在陆地棉中的渐渗情况,构建了一个来自于（陆地棉×克劳茨基棉）×陆地棉的BC₁ F₂群体,并用320个覆盖棉花基因组的SSR标记来监测外源种质的转入;只有38个标记在BC₁F₂群体中显示了分离,这些标记分布于14条染色体,组成了18个渐渗片段;通过比较发表的棉花遗传图谱,这18条渐渗片段的总长为595 cM;同时两个形态性状（黄色花瓣和开放花蕾）被定位于13号染色体。通过分子和形态鉴定,结果证实克劳茨基棉染色质已被渐渗进陆地棉遗传背景中。利用这种特异的标记将会促进理想的外源基因转入栽培棉。     

Morphological variation in Astragalus hamosus L. and Coronilla scorpioides L. populations of Tunisia

Morphological variation between Astragalus hamosus and Coronillascorpioides populations was studied using local germoplasm collected in northern and central Tunisia. Twenty-one morphological traits were recorded and data were analysed using complementary statistical analysis. Considerable variation based on morphological and agronomical traits was found between populations and for both species. Pod and peduncle lengths as well as flowers number were the most discriminant variables between populations. Differences were also found for variables like seed number per pod, seed yield and dry matter production. Significant correlations were found between plant traits and the environmental parameters of the origin sites. This study revealed enough variation among populations to initiate a selection programme for pasture improvement in arid and semi-arid areas of Tunisia, where the two species are well adapted. This revised version was published online in July 2006 with corrections to the Cover Date.     

Amplified fragment length polymorphism for variety identification and genetic diversity assessment in oleander (Nerium oleander L.)

Oleander is a Mediterranean evergreen shrub found along watercourses, gravelly places and damp slopes. It is grown widely as an ornamental for its abundant and long-lasting flowering as well as its moderate hardiness. Genetic relatedness among 71 accessions, including commercial varieties, different sources of the same varieties, and selections from the wild were investigated using amplified fragment length polymorphism (AFLP). Nine primer combinations yielded a total of 603 bands of which 241 were polymorphic. Genetic similarities among accessions were calculated according to Jaccard's Similarity Index and used to construct a dendrogram based on the unweighted pair group method using arithmetic averages. Our results show that the AFLP technique, which can simultaneously and assay a large number of loci randomly distributed in the genome, is much more informative on the genetic relationship and origin of accessions than the limited number of morphological characters conventionally used for variety discrimination. Up to about 9% molecular genetic differentiation was detected among morphologically indistinguishable provenances of the same variety; this can be partly attributed to scoring error but mainly to somatic variation occurring during vegetative propagation. On the other hand lower genetic distance values were sometimes found among varieties which differ in morphological characters and are thus commercialised with different names. The possibility of considering the amount of genetic variation within a variety as the threshold value for discrimination of initial varieties and essentially derived varieties is discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cytological and morphological variation in hybrid swarms and introgressed population of interspecific hybrids (Oryza rufipogon Griff. × Oryza sativa L.) and its impact on evolution of intermediate types

The morphology and cytology of selected hybrid swarms of wild and cultivated rices were studied following natural hybridization between the native species Oryza rufipogon Griff and exotic species Oryza sativa L. (var. Thaothabi and Moirangphoe). Similar studies were also conducted on populations developed through artificial hybridization of those two species. The morphological variation in plant height, anthocyanin pigmentation, Kernel and husk colour, sterility, presence of awns and grain shattering habits were similar in both natural (hybrid swarms) and artificially derived populations of interspecific hybrids. The cytological abnormalities such as quadrivalant formation at metaphase I, delayed separation, laggards and bridge formation, unequal separation and chromosomal elimination were also observed in both populations. These results indicated that the evolution of intermediate types had occurred due to genetic introgression from cultivated species to wild species. A systematic extinction of founder population was also noticed due to sudden ecological changes like deep submergence to medium submergence and human interference by growing cultivated species O. sativa L. in the area where wild species were being grown. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genetic diversity in Cynara cardunculus revealed by AFLP markers: comparison between cultivars and wild types from Sicily*

Genetic diversity in 49 plants of 16 accessions representing one wild and two cultivated taxa of Cynara cardunculus L. (wild cardoon, cultivated cardoon and globe artichoke) was investigated using amplified fragment length polymorphic (AFLP) analysis. Four pairs of primers identified a total of 264 scorable loci, 196 of which were polymorphic. The number of markers scored per primer combination ranged from 41 to 107, with an average of 66 markers per primer combination. All the primer combinations detected polymorphism. The data were used for cluster analysis and AMOVA. The clusters obtained are in agreement with the current botanical classification and the differences among the taxa were substantial. The eco‐geographical groups within wild cardoon are clearly separated in relative subclusters, and reflect the geography of the collection areas. The six clones of the four cultivated artichoke varieties were clearly separated into four subclusters, corresponding to the current classification which is based on morphological traits. The results obtained may have a direct and important bearing on plant genetic resource conservation and management and on breeding.     

野生稻与亚洲栽培稻的遗传多样性

为评价野生稻与亚洲栽培稻的遗传多样性及其变异关系,56对SSR引物被用于研究广泛地理分布的55份普通野生稻(其中32份O. rufipogon和23份O. nivara)和25份亚洲栽培稻(14份indica和11份japonica)样本。298个多态性位点被检出,占总扩增等位点的98.68%。野生稻多态性位点的百分比(平均达91%)及Nei’s遗传多样性值(h)明显高于亚洲栽培稻,表明普通野生稻比亚洲栽培稻具更丰富的遗传多样性。UPGMA聚类分析显示野生稻的两个类群(O. rufipogon和O. nivara)关系密切,但在遗传上存在明显的分化,支持其作为两个独立物种的分类观点。许多普通野生稻中籼粳分化尽管不很明显,然而亚洲栽培稻的籼粳亚种分化是明显的。亚洲栽培稻与多年生普通野生稻(O. rufipogon)关系更为密切,符合异源起源的遗传分化模式。     

Morphological and Yield Traits of Wild Legume (Tetragonolobus palaestinus Boiss) Populations

Through the process of domestication, cultivated crops have been selected from their wild ancestors for various anthropocentrically important characteristics. Tetragonolobus palaestinus Bioss is a wild grain legume species which grows naturally on the plains and hilly areas of north Jordan and neighbouring countries. In a study of agronomic and morphological traits of wild populations of T. palaestinus at two locations, the following variables were evaluated: number and dry weight of nodules per plant, plant height, number of branches and pods per plant, pod length, number of seeds per pod, 100-seed weight, and seed weight per plant. Positive and significant correlations between 14 pairs of variables were noted, including number and dry weight of nodules per plant, plant height, number of branches and pods per plant, pod length, and seed weight per plant. The wild populations of T. palaestinus studied here appeared to be homogenous, although some of the observed variation could have arisen from variation of the environmental conditions among locations.     

Genetic variation in South Korean natural populations of wild soybean (Glycine soja)

Summary Wild relatives are valuable genetic resources for crop improvement. Evaluating genetic variation in these species is not only important for their use in breeding programs, but will also provide information about evolution of crops. Seeds representing six natural populations were used to study the level of variation in the South Korean wild soybean. Electrophoretic assays of the seeds on horizontal slab gels were conducted to determine the genotypes of each natural plant at 35 loci in 17 isozymes and one protein. The results indicated a surprisingly high variation. The number of alleles at each locus was as high as four. Seventy two of the 94 reported alleles for the 35 loci were present in these populations. The average number of alleles per locus, 99% polymorphism and the expected heterozygosity in the total population were 2.1, 77.1% and 0.215, respectively. This amount of variation was not only higher than that reported for 857 soybean cultivars and wild soybean populations from other geographic regions, but also higher than the average for 123 self-fertilized plant species and 473 plant species of all mating systems. The high variation in the South Korean wild soybean as well as cultivated soybean indicated in this and other population genetic studies prompts us to propose that South Korea is one of the major soybean gene centers.     

Cytology and pollen grain fertility in populations of Astragalus adsurgens Pall. indigenous to Yunwu Mountain in the Loess Plateau,north-west China

Summary The wild type populations of Astragalus adsurgens Pall. growing on the northern slopes of Yunwu Mountain were investigated as a part of the program on the reclamation of the Loess Plateau, north-west China.In 1990, plants were sampled from two populations indigenous to Yunwu Mountain and Liupan Mountain, and two populations cultivated in experimental plots. Pollen grain fertility of the plants showed a wide variation from 20 to 99%. In 1991, cytological analysis of chromosome behaviour during meiosis was carried out in order to clarify the causal factors of pollen grain sterility. In anaphase-1, a chromatid bridge and an acentric fragment as well as two chromatid bridges were observed in high frequencies. In addition, more than two chromatid bridges per nucleus existed in considerably high frequencies.These observations clearly indicate that inversions are dominant in populations of wild A. adsurgens indigenous to Yunwu Mountain. xxThis study was supported by a Grant-in-Aid for scientific research from the Ministry of Education, Science and Culture, Japan (No. 01102023).